diff --git a/sys/cam/cam.c b/sys/cam/cam.c
--- a/sys/cam/cam.c
+++ b/sys/cam/cam.c
@@ -572,74 +572,3 @@
 	ccg->cylinders = ccg->volume_size / secs_per_cylinder;
 	ccg->ccb_h.status = CAM_REQ_CMP;
 }
-
-#ifdef _KERNEL
-struct memdesc
-memdesc_ccb(union ccb *ccb)
-{
-	struct ccb_hdr *ccb_h;
-	void *data_ptr;
-	uint32_t dxfer_len;
-	uint16_t sglist_cnt;
-
-	ccb_h = &ccb->ccb_h;
-	switch (ccb_h->func_code) {
-	case XPT_SCSI_IO: {
-		struct ccb_scsiio *csio;
-
-		csio = &ccb->csio;
-		data_ptr = csio->data_ptr;
-		dxfer_len = csio->dxfer_len;
-		sglist_cnt = csio->sglist_cnt;
-		break;
-	}
-	case XPT_CONT_TARGET_IO: {
-		struct ccb_scsiio *ctio;
-
-		ctio = &ccb->ctio;
-		data_ptr = ctio->data_ptr;
-		dxfer_len = ctio->dxfer_len;
-		sglist_cnt = ctio->sglist_cnt;
-		break;
-	}
-	case XPT_ATA_IO: {
-		struct ccb_ataio *ataio;
-
-		ataio = &ccb->ataio;
-		data_ptr = ataio->data_ptr;
-		dxfer_len = ataio->dxfer_len;
-		sglist_cnt = 0;
-		break;
-	}
-	case XPT_NVME_IO:
-	case XPT_NVME_ADMIN: {
-		struct ccb_nvmeio *nvmeio;
-
-		nvmeio = &ccb->nvmeio;
-		data_ptr = nvmeio->data_ptr;
-		dxfer_len = nvmeio->dxfer_len;
-		sglist_cnt = nvmeio->sglist_cnt;
-		break;
-	}
-	default:
-		panic("%s: Unsupported func code %d", __func__,
-		    ccb_h->func_code);
-	}
-
-	switch ((ccb_h->flags & CAM_DATA_MASK)) {
-	case CAM_DATA_VADDR:
-		return (memdesc_vaddr(data_ptr, dxfer_len));
-	case CAM_DATA_PADDR:
-		return (memdesc_paddr((vm_paddr_t)(uintptr_t)data_ptr,
-		    dxfer_len));
-	case CAM_DATA_SG:
-		return (memdesc_vlist(data_ptr, sglist_cnt));
-	case CAM_DATA_SG_PADDR:
-		return (memdesc_plist(data_ptr, sglist_cnt));
-	case CAM_DATA_BIO:
-		return (memdesc_bio(data_ptr));
-	default:
-		panic("%s: flags 0x%X unimplemented", __func__, ccb_h->flags);
-	}
-}
-#endif
diff --git a/sys/cam/cam_ccb.h b/sys/cam/cam_ccb.h
--- a/sys/cam/cam_ccb.h
+++ b/sys/cam/cam_ccb.h
@@ -1553,6 +1553,79 @@
 	nvmeio->data_ptr = data_ptr;
 	nvmeio->dxfer_len = dxfer_len;
 }
+#ifdef _KERNEL
+#include <sys/memdesc.h>
+
+static inline struct memdesc
+cam_memdesc_ccb(union ccb *ccb)
+{
+	struct ccb_hdr *ccb_h;
+	void *data_ptr;
+	uint32_t dxfer_len;
+	uint16_t sglist_cnt;
+
+	ccb_h = &ccb->ccb_h;
+	switch (ccb_h->func_code) {
+	case XPT_SCSI_IO: {
+		struct ccb_scsiio *csio;
+
+		csio = &ccb->csio;
+		data_ptr = csio->data_ptr;
+		dxfer_len = csio->dxfer_len;
+		sglist_cnt = csio->sglist_cnt;
+		break;
+	}
+	case XPT_CONT_TARGET_IO: {
+		struct ccb_scsiio *ctio;
+
+		ctio = &ccb->ctio;
+		data_ptr = ctio->data_ptr;
+		dxfer_len = ctio->dxfer_len;
+		sglist_cnt = ctio->sglist_cnt;
+		break;
+	}
+	case XPT_ATA_IO: {
+		struct ccb_ataio *ataio;
+
+		ataio = &ccb->ataio;
+		data_ptr = ataio->data_ptr;
+		dxfer_len = ataio->dxfer_len;
+		sglist_cnt = 0;
+		break;
+	}
+	case XPT_NVME_IO:
+	case XPT_NVME_ADMIN: {
+		struct ccb_nvmeio *nvmeio;
+
+		nvmeio = &ccb->nvmeio;
+		data_ptr = nvmeio->data_ptr;
+		dxfer_len = nvmeio->dxfer_len;
+		sglist_cnt = nvmeio->sglist_cnt;
+		break;
+	}
+	default:
+		panic("%s: Unsupported func code %d", __func__,
+		    ccb_h->func_code);
+	}
+
+	switch ((ccb_h->flags & CAM_DATA_MASK)) {
+	case CAM_DATA_VADDR:
+		return (memdesc_vaddr(data_ptr, dxfer_len));
+	case CAM_DATA_PADDR:
+		return (memdesc_paddr((vm_paddr_t)(uintptr_t)data_ptr,
+		    dxfer_len));
+	case CAM_DATA_SG:
+		return (memdesc_vlist(data_ptr, sglist_cnt));
+	case CAM_DATA_SG_PADDR:
+		return (memdesc_plist(data_ptr, sglist_cnt));
+	case CAM_DATA_BIO:
+		return (memdesc_bio(data_ptr));
+	default:
+		panic("%s: flags 0x%X unimplemented", __func__, ccb_h->flags);
+	}
+}
+#endif
+
 __END_DECLS
 
 #endif /* _CAM_CAM_CCB_H */
diff --git a/sys/kern/subr_bus_dma.c b/sys/kern/subr_bus_dma.c
--- a/sys/kern/subr_bus_dma.c
+++ b/sys/kern/subr_bus_dma.c
@@ -463,7 +463,7 @@
 		return (0);
 	}
 
-	mem = memdesc_ccb(ccb);
+	mem = cam_memdesc_ccb(ccb);
 	return (bus_dmamap_load_mem(dmat, map, &mem, callback, callback_arg,
 	    flags));
 }
diff --git a/sys/sys/memdesc.h b/sys/sys/memdesc.h
--- a/sys/sys/memdesc.h
+++ b/sys/sys/memdesc.h
@@ -36,7 +36,6 @@
 struct uio;
 struct mbuf;
 struct vm_page;
-union ccb;
 
 /*
  * struct memdesc encapsulates various memory descriptors and provides
@@ -153,6 +152,5 @@
 }
 
 struct memdesc	memdesc_bio(struct bio *bio);
-struct memdesc	memdesc_ccb(union ccb *ccb);
 
 #endif /* _SYS_MEMDESC_H_ */